Near Real Time

From MTConnect® User's Portal
Jump to: navigation, search

MTConnect supports the ability to receive changes in near real time. The reference implementation of the MTConnect Agent written in C++ has this capability and has been validated to propagate changes from the adapter first reporting the even to the client application in between 3-10ms depending on the platform. For a reasonably recent computer with a CPU > 500Mhz the agent can easily handle a 5ms latency.

To request data with as little latency as possible, use the interval option and set the value to 0. This means to send data every 0 ms. The MTConnect standard specifies that if no data is available, then the agent will only need to send out a heartbeat every n seconds where n defaults to 10 seconds or can be set with the heartbeat option on the URL. So, the URL will look like this:

 http://example.com:5000/sample?interval=0&heartbeat=1000

This will send data immediately when it arrives and send a heartbeat every second to the client. A heartbeat will allow the client to detect a disconnect or failure within 2x heartbeat ms; in this case you can detect a failure within 2 seconds. In this case we are defining failure as the agent fails and the client application can't detect the failure, such as the network was disconnected or the machine was powered off.

This will also require that the application consumes MTConnect Streaming data.